Trauma and stress initiate the systemic inflammatory response, resulting in the production of pro-inflammatory cytokines, such as TNF-alpha, IL1beta and IL-8. Production of these pro-inflammatory cytokines by monocytes and macrophages (mphi) is regulated by NF-kappaB. TNF- alpha activates this transcription factor, leading to further amplification of the inflammatory response. Indeed, blocking TNF-alpha can attenuate the inflammatory response. However, it remains to be determined what roles the p55 and p75 TNF receptors have in the regulation of the inflammatory response. Trauma and stress also induce a group of cytoprotective proteins. Our previous studies demonstrate that the expression of heat shock protein 72 (hsp72) IN CARDIAC Mphi inhibits myocardial TNF-alpha production induced by ischemia/reperfusion, and enhances cardiac resistance to contractile depression associated with trauma and stress are the focus of our application. Utilizing a liposomal HSP72 delivery system, we will investigate HSP72 regulation of the inflammatory response to trauma and stress, and interrogate the regulatory mechanism at multiple levels from cells to animal models. We hypothesize that HSP72 blunts TNF receptor-mediated amplification of pro-inflammatory cytokine expression and that delivery of HSP72 attenuates the cellular and tissue inflammatory response to trauma and stress. Furthermore, we propose that liposomal delivery of HSP72 will shift the anti- and pro-inflammatory balance and permit protection of the myocardium against injury in elective surgery involving obligatory myocardial trauma and stress. The proposed studies will: 1) delineate the role of HSP72 in the regulation of pro-inflammatory cytokine (TNF- alpha, IL-1beta and IL-8) production is Mphi (with Project VII), 2) investigate the mechanism by which HSP72 regulates cytokine production (with Project VIII), 3) define the role of TNF receptors in the amplification of Mphi pro-inflammatory response (with Projects IV, VI and VIII), 4) determine the influence of HSP72 on TNF receptor- mediated amplification of the pro-inflammatory response in Mphi, 5) examine activation of NF-kappaB by TNF-alpha requires cytoskeletal reorganization (with Projects IV, VI and VIII), 6) determine whether HSP72 stabilizes cytoskeletal architecture (with Project VIII), and 7) explore the therapeutic potential of HSP72 in suppressing the cardiac inflammatory response to trauma and stress in isolated heart and in animal models (with Projects III, VI, VII, VIII and IX). Delineation of HSP72 regulation of the inflammatory response to trauma and stress will permit exploring an anti-inflammatory strategy with an endogenous stress protein. Investigation of TNF receptor signaling in the regulation of the inflammatory response will provide valuable information for therapeutic control of post-traumatic myocardial depression.